Crossover flow device



April 6, 1948. M'. 1'. woRKs 2,439,327

Y CROSSOVER FLOW DEVICE Filed oct; 26, 1945 :s sheets-sheet 1- EEJ; mill MADDEN T. WORKS INVENTOR Apri; 6, 194s.

M. T. woRKs I A 2,439,327 CBOSSOVER FLOW DEVICE Filed hat. 26, 1943l s sheets-sheet 'a E E E- l; a8 a 57 .T E Q MDDEN T. WORKS INVENTOR 'Patented Apr. e, 194sy cRossovEn FLOW DEVICE Madden T. Works, Houston, Tex., asslgnor to Cameron Iron Works, Houston, Tex., a corporation of Texas Application october ze, ma, serial No. 507,111

17 Claims. 1

This invention relates to a means for providing appropriate connection between vertically spaced sources of flow production and the interior and exterior respectively of a flow tubing'within a well, and has for its general object the provision of such a device which will make possible the ilow from a lower producing zone through the annular space about the tubing to the surface of the ground and the ow from an upper producing zone through' the tubing itself, while at the same time providing means whereby the well may be properly Washed before it is completed.

Invflnishing an ordinary oil or gas well, it is customary to run in a casing or large pipe and to cement this pipe in place either with its bottom end resting on the bottom of the well or with its lower end anchored just abover the lowermost producing formation with the cement serving the lpurpose of sealing off the leakage from higher formations through which the Well passes. If

the casing is set to the bottomy of the well then it is perforated either mechanically or by shooting holes through it at the level of the lowermost producing formation. If the casing is set above the lowermost producing formation, then the hole may be left open at the bottom or a screen may be set extending downwardly from the lower end of the casing through the producing formation.

In either event there is then lowered into the casing a much smaller pipe known as the tubing. This tubing carries an element known as a packer which may be expanded after the tubing is in 4place with its lower end opposite the producing formation, so as to close the annular space between the tubing and the casing' and make all fluid coming into the casing below the packer flow into the tubing and out of the well through the tubing. Such packers have, however, been s o constructed that prior to the setting of the packer in the manner just described it is possible to pump down through the tubing a, suitable liquid for the purpose of washing mud and the like from the well and placing it in condition for flow. During such washing operation the washing fluid is pumped downwardly through the tubing, emerging from the bottom end thereof, and thus washes the well from the bottom up with the return of the washing fluid up around the outside of the tubing past the packer which has not been set and thence to the surface of the ground through the annular space within the casing about the tubing.

An example of one such form of ordinary tubing packer is disclosed in the copending patent lthe gas bearing formation is the higher of the two formations, the well is completed just as before except that additional perforations in the casing are provided at the level of the higher producing formation so that the ow :may take place into the casing from the higher formation. The tubing and packer are then run as before and the packing set between the two sets of perforations or in other words between the levels of the two producing formations. In such a case it will be readily seen that the production from the lower formation will flow intoV the casing below the packer and thence up to the surface of the ground through the tubing, but will be prevented from owing up through the casing by the presence of the packer around the tubing. The production from the upper formation will. simultaneously flow into the casing and up to the surface of the ground through theV annular space about the tubing within 'the casing.`

However, in some c ases a situation is encountered in which the .upper of the two producing formations produces oil whereas the lower of such formations produces gas, and in such situations considerable dimculty is encountered due to the fact that certain of the States have laws and regulations requiring that when a well is produced from two formations simultaneously and one of those is a gas bearing and the other an oil bearing formation, the flow from the oil bearing formation must take place through the tubing and that from the gas bearing formation through the annular space surrounding the tubing within the casing. Regardless of Whether the jurisdiction involved has such a regulation or not, it

is desirable that the oil flow to the surface ofthe ground through the tubing and the gas through the casing for various other reasons. It will readily be seen that with the conventional packer arrangement for setting the tubing with the packer located between the two producing formations, oil would be produced through the annular space surrounding the tubing in any case where the oil producing formation is the higher of the two.

I have heretofore devised and have set forth and claimed in my copending application, Serial No. 505,782, filed the 11th day of October 1943, a device which will make possible the flow 3 y of production from a higher formation in the well through a tubing extending into the well, and the independent and simultaneous production from a lower formation in the same well through the annular space surrounding the tubing. In that apparatus, however, if a washing fluid is pumped downwardly through the tubing prior to the setting of the crossover packer, such washing iluid will not be forced to go entirely to the bottom of the well before emerging from the tubing, but may escape through the openings through which it is intended that the upper zone of production shalllater ow into the tubing. The washing fluid may. therefore, return through the casing to the surface of the ground from this point and the lower portion of the well may not be thoroughly washed.

It is an object of this inventionto provide a crossover flow device through which it will be possible before setting the packers involved to force washing fluid all the way to the bottom of the well and thus wash the well thoroughly from the lbottom thereof and not merels1 from some higher point adjacent an upper producing formation.

Another objectV of this invention is to provide a crossover flow device of the character referred to in which during the setting operation fluid pumped downwardly through the tubing will pass to the lower end of thewell, but after the setting operation fluid owing from the lower end of the Wellwill be diverted into the annular space about the tubing while fluid flowing from a higher point in the well will be caused to flow upwardly to the surface of the ground through the tubing.

Another object of this invention is to provide a device of the character referred to which will lbe a unitary assembly capable of being lowered on the tubing through which the well is to be produced and capable of being set inv position and placed in flowing condition by manipulation of the tubing'.

Yet another object of this invention is to provide a' device of the character referred to in which after the crossover flow device and the usual tubing packer have both been set, they may be released and further washing to the bottom of the well may |becarried out. i

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawing wherein is set forth by'way of illustration and example only and not by way of limitation, one embodiment of this invention.

In the drawing:

Fig. 1 is a longitudinal cross section through the upper portion of a crossover flow device constructed in accordance with this invention, the same being illustrated in place within a well casing.

Fig. 2 is a continuation of the lower portion of Fig. 1, both of these figures illustrating the device in condition in which it would be before being set for flowing the well, and with the parts in such position as to permit washing the well to the bottom thereof.

Fig. 3 is a view simi-lar to Fig. 1 but illustrating vthe parts in position which they will occupy after Fig. 6 is a similar horizontal cross section taken along the line 8-8 of Fig. 3. l

Referring now more in detail to the drawing, the numeral I indicates the conventional well casing in which is illustrated a device constructed in accordance with this invention.

The device illustrated is adapted to be lowered upon a section of tubing, the same being coupled to the upper end lof the nipple 2 which forms a continuation of the lower end of the tubing, and this nipple 2 at its lower end extends into a collar or coupling 3. Registering lateral openings are provided in the lower end of the nipple 2 and the coupling 3 as shown at 4, and the nipple 2 may be secured in place in any desired manner such as by welding. Y

Threaded into the lower end of the coupling 3 is a telescoping tubing section 5 having its upper end within the coupling 3 plugged or blocked oi by means of a disc 8 or other similar obstruction, which is illustrated as welded in place by weld 1.

The tubing section 5 a short distance below the adapted to fit Within the keyways I4 in a nipple I5 that is threaded into the lower end of the collar l2, so as to provide a connection which is slidable but through which the tubing section may be utilized for the purpose of rotatingthe nipple I5 and its associated parts.

To the lower end of the nipple I5 is threadedly secured a, collar I6, and a suitable tail pipe representing a continuation of the tubing section that extends through the device is illustrated at I1 as being connected to the collar I6.

'I'he lower end of the nipple 2, together with the collar 3 and the upper end of the tubing section 5, are located in Fig. 1 within a housing section I8 which adjacent its upper end is provided with sealing means I9 held in place by a nut 20 for the purpose of providing a sliding seal about the nipple 2. At its lower end, this housing I8 is threaded at 2| but is providedwith an external downwardly facing shoulder 22 adapted to receive the upper end of a second housing section 23. The extent of the shoulder 22 and the thickness ofthe upper end of the housing section 23 are such that there will be a flush joint-be- 4 gagement therewith the thin walled upper section of the sleeve-like member 26. This sleevelike member is welded in place as shown at 21 and the members 25 and 26 are provided with registering lateral openings 28.

The outer surface of the reduced section 25 of the housing member 23 is provided with longitudinal passageways 29-so that when the sleevelike portion 23 is placed thereovei. these lungitudinal passageways, taken with the lateral openings III and 3| into the interior of the device, will form by-passes for conducting i'luid Vpast the zone in which 'the lateral openings 23 are located.

The lower end portion of the housing section i 23 is provided with an internal upwardly facing shoulder 32 which is opposed to and spaced a substantial distance from the internal downwardly facing shoulder 24 provided on the lower` end of the housing section I3.

The lower engl portion of the sleeve-like ele- A flange 35 which is adapted to receive and retain the upper end portion of the annular packing ring 33 surrounding the mandrel 34. Adjacent the lower end ofthis packing 33 is a floating spacer element 31 having an upwardly extending flange 33 opposed to the flange 35 and adapted to engage and retain the lower portion of the packing 35. Likewise, extending downwardly from the element 31 is still another flange-like portion 33 adapted to engage and retain the upper por.. tion of the packing 43 which is similar in all respects to the Packingvlll A packing retaining and abutment member 4| surrounds the mandrel or conduit 34 below the packing 40 and is provided with an upwardly extending flange 42 adapted to engage and retain the lower portion ot such packing. 'I'his element 4I, like the element 31, is slidable upon the exterior of the conduit 34 and when moved upwardly with respect to the element 35 is adapted to compress both the packings 33 and 43 and cause them to expand laterally into engagement with the interior of the casing I as illustrated in Figs. 3 and 4. A short sleeve 43 is externally threaded to the lower end of the mandrel 34 and provides an upwardly facing externall shoulder for the purpose of retaining the annular abutment member 4I in place on the mandrel.

Threaded to the lower portion of the abutment 4I is an elongated sleeveflike member 44 having perforations therein so as to to permit i'ree flow between the interior and the exterior of this member. The lower end of this member is threaded to the coupling I2 hereinbefore referred to. 4

Interposed between the coupling I2 and the lower end of the short sleeve 43 is a compression lspring 45 which serves at all times to urge the packing abutment 4I toward its lowermost position .with respect to the mandrel 34 and the abutment 35, thus holding the parts in position to prevent the expansion of the packing into sealing engagement with the'casing wall.

Interposed between thetubular member 5 and the housing member 23 and lying between the shoulders 24 and 32 is an annular double piston valve element. This valve element is made up of a number of parts including a cage-like element having packing abutments 43 and 41 spaced` apart by circumferentially spaced connectors 48. Against the upper of these packing abutments l1 are disposed a pair of annular packing rings 49 having an annular spacer 53 between them. Likewise, disposed against the lower of the two abutments 43 is a pair of annular packing rings 6I4 having an annular spacer 52 between them. The upper of the packing rings 43 bears against a pressure plate 33 which isof annular form and substantially the same width as the packing 43,

and the lower ci the packing rings 5I bears against a similar pressure plate 54.

A plurality of tie members in the form of rods 55 are welded at circumierentiallyV spaced intervals to the pressure plate 54 and extend throughthe packing rings 5I and the spacer 52 as wellas v through the packing abutment 43, where they are secured in place by cotter keys 51 or the like. Likewise. a plurality of tiemembers 53 of similar formation are welded as at 53 or otherwise secured to the pressure plate 53, and extend through the packing rings 43 and the spacer 50 and through the abutment' 41, being secured in' place by means of cotter keys or the like extending through their inner ends.

It is to be noted that when the weight of thev device is hanging on the tubing connection 2, this element, together with the tubing section 5 will be moved to its uppermost position with respect to the other elements of the apparatus, so that the ring 9 0n the tubular member l will engage the lower pressure `plate 54 oi' the double piston valve and will move this valve as a whole upwardly until it contacts the shoulder 24. Meantime, the tubing member 5 will have moved upwardly as far as possible with respect to the 'piston valve, thus exposing the openings 3 above the upper end of the valve, and both the openings 8 and the openings 4 will be uncovered within the annular space inside the housing and above the valve. 'Ihis will make it possible to pump down through the tubing, out through the open` ings 4, back in through the openings 3, and g thence through the tubing unit 5, the nipple I5,

' and the tail pipe I1 to the Ibottom of the well to wash the same.

At the same time, with the double piston valve in its uppermost position with respect to the housing member 23, it lwill be seen that the upper endl 3| of the by-pass 23 will be closed,

' thus preventing ow through such by-pass, while ,the lateral opening 23 will be uncovered, thus permitting part of the return from the bottom of the well to come through perforatiozis in the sleeve 44, up through the annular space outside of the tubing unit 5, and out through the lateral opening 23 into the annular space'within the casing I, and thence to the surface of the ground.

While the parts are in the position just described, the conduit 34 and the packing abutment 35 will be held by the piston valve in theiruppermost position, while the weight of the tail pipe I'I, the nipple I5, and the pipe 44, will serve to pull the lower packing abutment 4I downwardly as far as possible and thus relieve any tendency toward the longitudinal compression and consequent lateral expansion of the packing rings 36 and 40.

After the device has been lowered to the point where it is desired that .it be set, and after the4 well has been washed in the manner just referred to, the tubing connected to the nipple 2 may then be lowered until the parts attached to the tail pipe I 1 contact the bottom of the well or a suitable abutment therein, whereupon the usual well packer which is secured to the tail pipe Il will be set in the usual manner, and downward movement of the tubing will take place with respect to the housing members I3 and 23. When this downward movement takes place, the double piston valve element may move downwardly with the tubing initially until it strikes the shoulder 32, whereupon the tubing will -move downwardly with respect to the valve element until the lower end of 'thecoupling 3 comes in contact with the upper` pressure plate 53. Ii' it so happens that the piston valve grips the housing member 23 more tightly than it does the tubing, then the tubing will move downwardly within the valve until the lower end of the coupling 3 contacts the pressure plate 53, whereupon the piston unit will will begin to move downwordly with the tubing until the lower pressure plate 54 contacts the shoulder 32. In either event, the placing of weight on the tubing will exert a longitudinal force upon the annular packing rings 43 and 5| respectively and cause them to expand laterally into close sealing engagement withthe inside of the housing member 23 and with the exterior of the tubing member 5. This. weight will also cause downward movement of these housing members i8 and 23 together with the packing abutment 26, being transmitted thereto through the double piston valve unit. This downward movement of the packing abutment 23 will cause downward movement of the mandrel 34 with respect to the lower packing abutmentl Il. Thus, both packing rings 36 and 40 will be compressed longitudinally and caused to expand laterally into full sealing engagement with the inner surface of the casing I.

The condition of the apparatus will then be ,illustrated in Figs. 3 and 4, and it will be seen that flow from within the casing below the packings 36 and 4B may come in through the perforations in the pipe M, thence upwardly through the annular space between the mandrel and the tubing member, through the by-pass 23, and then in through the openings I into the interior of the tubing, flowing through the tubing to the surface of the ground.

.At the same time, production from the lower formation coming up through the tail pipe l1 will iiow upwardly through the tubing member 5 and out through the lateral openings 8 between the upper and lower sets of packing rings of the double piston valve, out through the openings 28, and into the annular space between the tubing and the casing, through which it will `iiow to the surface of the ground.

It will thus be seen that after the device has been set as just described, production from a higher formation may be caused to flow to the surface of the ground through the tubing connected to the nipple 2, whereas production from a lower formation may be caused to ow to the surface of the ground through the annular space between the tubing and the casing.

It will be seen, therefore, that by the apparatus whichvhas been shown'and described, a means is provided which will make possible the pumping of washing iiuld downwardly through the tubing to the bottom of the well and up around the outside of the tubing and past the packers thereon to the top of the well so that the well may be washed all the way to the bottom. Then the device may be set in such a manner as to make possiblethe production from a lower formation which may be a gas bearing formation, and from a higher formation which may be an oil bearing formation, with the production from the lower formation flowing upwardly from the apparatus of this invention to the surface of theA ground through the annular space between the tubing and the casing, and with the production from the higher formation, iiowing upwardly through the tubing to-the surface of the ground.

A device has thus been produced which may be interposed in a well tubing abovethe usual packing and make possible the accomplishment oi' the objects sought by this invention.

Having described my invention, I claim: A

1. In a crossover iiow device adaptable for use in a well bore having two producing formations,

a conduit assembly having upper and lower lateral openings and upper and lower endwise openings. passageways interconnecting said openings, valve means interposed in said passageways and shiftable to either of two positions, said valve means in one position providing vindependent communication between said upper and lower lateral openings and between said upper and lower endwise openings respectively, and when in the second position providing independent communication between the lower lateral opening and the upper endwise opening and between the lower endwise opening, and the upper lateral opening respectively, means for shifting said valve from one position to another, and an yannular seal forming means embracing said assembly between said upper and lower lateral openings adapted` with the valve means in the second position, tol separate the passageway including the lower endwise opening from the upper producing formation.

2. In a crossover flow device adaptable for use in a well bore having two producing formations, a conduit assembly having upper and lower lateral openings and upper and lower endwise openings, passageways interconnecting said openings, valve means interposed in said passageways and shiftable to either of two positions, said valve means in one position providing independent communication between said upper and lower `lateral openings and between said upper and lower endwise openings respectively, and when in the second position providing independent communication between the lower lateral opening and the upper endwise opening and between the lower endwise opening and the upper lateral opening respectively. means for shifting said valve from one position to the other, annular sealing means embracing said assembly between said upper and lower lateral openings adapted with the valve means in the second position, to separate the passageway including the lower endwise opening from the upper producing formation, said assembly including parts relatively movable for actuating said sealing means to sealing position,

and further including means interconnecting lateral openings and between said upper and lower endwise openings respectively when said valve is in one position, and for providing independent communication between the lower lateral opening and the upper endwise opening and tween the lower endwise opening and the upper lateral opening, respectively when in another position, said assembly including relatively movable parts, and said valve being movable with respect to both parts and each of said parts having means thereon to engage and shift said valve from one position to the other with respect to the other part when said parts are moved with resembly having upper and lower lateral openings and upper and lower endwise openings, passageways interconnecting said openings, valve means interposed in said passageways and shiftable'to either of two positions for providing independent communication between said upper and lower lateral openings and between said upper and -lower endwise openings respectively when said valve is in one position, and for providing independent communication between the lower lat eral `opening and the upper endwise opening and between thelower endwise opening and the upper lateral opening, respectively when in another position, said assembly including relatively movable parts, one of said parts having means (l, 3) thereon adapted to engage and shift said valve from one position to another with respect to the other part when said parts Vare moved with respect to each other, said valve having expansible packing, and means (53, 5l) forming part of said valve movable to expand said packing to sealing position when said valve is in either postion.

5. In a crossover flow device. a conduit assembly having upper and lower lateral openings and upper and lower endwise openings, passageways interconnecting said openings, valve means interposed in said passageways and vshiftable to either of two positions for providing independent communication between said upper and lower` lateral openings and between said upper and lower endwise openings respectively when said valve is in one position, and for providing indepositions respectively with reference to said valve,

pendent communication between the lower lateral opening and the upper endwise opening and between the lower endwise opening and the upper lateral opening, respectively when in another position, said assembly including relatively movable parts, one of said parts having means (9, 3) thereon adapted to engage and shift said valve from one position to another with respect to the other part when said parts are moved with respect to each other, said valve having expansible packing and means (53, 54) forming part oi said valve in the path of said valve engaging means on said movable part and engageable and movable by said valve engaging means to expand said packing to sealing position after said valve has been shifted by said valve engaging means.

6. In a crossover flow device adaptable i'or use in a well bore having two producing formations, y

an assembly having endwise openings and upper and lower lateral openings, and means for selectively providing either independent passageways between said endwise openings and between said lateral openings or independent passageways between each endwise opening and the lateral opening most remote therefrom, and expansible annular seal forming means embracing said assembly between said lateral openings adapted when expanded to separate the passageway including the lower endwise opening from the upper producing formation.

'7. In a crossover ow device adaptable for use in a well bore having two producing formations, an assembly having endwise openings and upper and lower lateral openings, and means for selectively providing either independent passageways between said endwise openings and between said lateral openings or independent passageways be- 10 tween each endwise opening and the lateral opening most remote therefrom, said assembly including the lower endwise opening from the upper producing formation.

8. In a crossover ilow device, an assembly including spaced concentric relatively slidable conduits, means separating the upper and lower portions of the inner conduit, each such portion having its free end open and having a lateral opening into the space between said conduits adjacent said separating means, said outer conduit having a lateral opening therefrom intermediate its ends, being `sealed about said inner conduit at one end and open at the other, and having a -by-pass around the zone adjacent said last mentioned lateral opening, and an annular double piston valve slidable in the space between said conduits and with respect to both conduits, said conduits being'slidable to one extreme position with respect to each other to slide one of said conduits to one extremity of its travel with respect to said valve and to slide the other conduit to the opposite extremity of its travel with respect to the valve, and said conduits being slidable to the other extreme position with .respect to each other to slide them to their other extreme said valve when in the first mentioned extremi- .ties of its travel with respect to said conduits shutting ofl.' said by-pass and uncovering the lateral opening from said outer conduit to place it in communication with the open end thereof, and uncovering on its opposite side and within the closed oif zone of the outer conduit the lateral openings from both portions oi' the inner conduit to place the two portions thereof in communication with each other, and when in the second mentioned extremities of its travel with respect to said conduits having the space between its pistons registering with the lateral opening in the outer conduit and the lateral openings in one of the portions of the inner conduit to place the interior of said one portion of the inner conduit in communication with the exterior of the outer conduit in communicationV with the other portion of the inner conduit through said by-pass and the lateral opening in the other portion of the' inner conduit.

9. In a crossover flow device adaptable for use in a well bore having two producing formations, an assembly including spaced `concentric relatively slidable conduits, means separating the upper and lower portions of the inner conduit, each such portion having its free end open and'having a lateral opening into the space between said conduits adjacent said separating means, said outer conduit having a lateral opening therefrom intermediate its ends, being sealed about said inner conduit at one end and open at the other, and having a by-pass around the zone adjacent said last mentioned lateral opening, and an annular double piston valve slidable in the space between said conduits and with respect to both conduits, said conduits being slidable to one extreme position with respect to each other to slide one of said conduits to one extreme of its travel with respect to said valve and to slide the other @Qlidllf Q the opposite extremity of itsV travel with respect to the valve, and said conduitsbeing slidable to the other extreme position with vrespect to each other to slide them to their other in communication with the open end thereof, and

uncovering on its opposite side and within the closed of! zone of the outer .conduit the lateral .openings from @oth portions of the inner conduit to place the twop'ortions thereof in communication with each other, and when in thel second mentioned extremities of its travel with respect to said conduits having the space between its pistons `registering with the lateral opening vin -the-,outerfrconduit and the lateral openings in one ofthe portions of the inner conduit to place thelinterior of saidone portion of the inner conduitfin' communication with the exterior of the` outer conduit, and lying between the extremities of said` by-pass` yto place the open end .of the outer conduit in communication with the other portion of the inner conduit through said bynass and the lateral opening in the other portion of the inner conduit. said outer conduit having relatively movable parts providing opposed shoulders about itsY exterior between the lateral opening in the outer conduit and the open end thereof, and annular seal forming means about the exterior thereof between said shoulders adapted when the valve'is'in its second extreme position to separate the passage exterior of the outer conduit leading to its upper end from the upper producing formation.

10. In a crossover flow device, an assembly including spaced concentric relatively slidable conabutments and a skeleton framework joining them together, annular laterally expansible sealing means carried by said abutments, an annular e pressure plate on that face of each packing opposite its abutment, and lost motion means for joining said plates to said cage.

1,2. As a subcombination, a piston type slide valve for a crossover flow device, comprising a pair of annular packings, a rigid openwork spacer between them, a pressure plate on each of the remote extremities of said packings respectively,

l and lost motion means for joining all of said elements together.-

13. As a, subcombination, a piston type slide valve for a crossover ow device, comprising an annular cage consisting of two annular packing abutments and a skeleton framework joining them together, an annular packing on each abutment, an annular pressure plate on each packing,

a pluralityof. tie members secured to-said pressure platesrespectively and extending through said packings and 'slidingly engaging said abutments, and means for preventing said. tie members from being disengaged from said abutments.

14. As a subcombination, a piston type slide valve for a crossover flow device, comprising an annular cage consisting of two annular packing abutments of substantially the same width as the space. within which the valve is adapted to seal, and a skeleton framework joining jsaid abutments together, annular laterally expansible sealing 'means carried by said abutments, an annular duits, means separating the upper and lower Y portionsof the inner conduit, each such portion having its free end open and having a lateral opening into the space between said conduits adjacent said separating means, said outer conduit having a lateral opening therefrom intermediate its ends, being sealed about said inner conduit posite side and within the closed of! zone of the outer conduit the lateral openings from both portions of theinner conduit to place the two portions thereof in communication with each other, and when in its opposite extreme position with respect to each conduit having the space between its pistons registering with the lateral opening in the outer conduit and the lateral openings in one of the portions of the inner conduit to place the interior of said one portion of the inner conduit in communication with the exterior of the outer conduit, and lying between the extremities of said by-pass to place the open end of the outer conduit `in communication with the other portion of the inner conduit through said by-pass and the lateral opening in the other portion of the inner conduit. v

1l, As a subcombination, a piston type slide valve for a crossover flow device, comprising an annular cage consisting of two annular packing pressure plate of substantially the same width as said abutments and disposed on that face of each packing opposite its abutment, and lost motion means for joining said plates by said cage:

15. In a crossover flow device, an assembly having endwise openings and upper and lower lateral openings, and means for selectively providing either independent communication between said endwise openings and between said lateral openings or independent communication between each endwise opening and the lateral opening most remote therefrom, said assembly including relatively movable parts, said iirst means being shiftable by said parts and including seal forming i means expansible by said parts to sealing'position upon relative movement of said parts to the limit of such movement in either direction.

16. A crossover iiow device comprising an assembly adapted to be located in a casing and havin'g pipe connections adjacent its` opposite ends, longitudinally spaced lateral openings, and passageways interconnecting all of said pipe connections and openings with each other, a packing surrounding said assembly between said lateral openings adapted to form a seal about the assembly within said casing and divide the annular space between theassembly and the casing into two parts in communication with said lateral openings respectively, and a four-way valve within said assembly controlling said passage ways and operable when in one position to provide having endwise opening tubing connections and able when in one position to provide a by-pass between .the exterior of said assembly above and below said packing by connecting said lateral openings with each other, and simultaneously and independently to connect said endwise openings with each other, and operable when in vanother position to connect the endwise opening at the,

lower end of the assembly with the lateral opening above said packing means, and an independent connection between the lateral opening below said 14 packing means and the endwise opening at the upper end of said assembly.

MADDEN 'T. WORKS. REFERENCES CITED The following references are of record in the 111e of this Patent:

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